Insulated electric conductor.



No. 839,374. 7 PATENTED DEC. 25, 1906. W. L. R. EMMET & W. S. CLARK. INSULATED ELECTRIC CONDUCTOR APPLICATION FILED NOV. 9. 1901.

Inventors Eimrnefl WiHiamLeFqg Wallace 5 Witnesses:

UNITED STATES: PATENT- OFFICE.

WILLIAM L. R. EMMET AND WALLACE s. CLARK, or sCnENECrADY, NEW YORK, AssIeNoRs T GENERAL ELECTRIC COMPANY, A CoR- PORATION or NEW YORK. 1

lNSULATED: ELECTRIC CONDUCTOR.

No. 839,374. Specification of Letters Patent. Patented Dec. 25, l9Q6. i Application filed ll ovembsr 9,1901. Serial No- 81,658. I

To all whom it may concern.- the first but with the joints lapped. In the Be it known that we, WILLIAM LE ROY same way the cable is built up of a number EMMET and WALLACE S. CLARK, citizens of of superposed layers having overlapping the United States, residing at Schenectady, joints with a viscous substance intervening county of Schenectady, State of New York, between the several layers, permitting it to have invented certain new and useful lmbe bent or distorted with impunity and beprovements in Insulated Electric Conductors, ing proof against the infiltration of moisture of which the following is a specification. and retaining for an indefinite length 01"? time This invention relates to insulated electric its high insulating properties. After the conductors, with a view to providing a con final covering has been applied an armor of ductor orcable having high insulating prop-, lead or other suitable material may be aperties, being thoroughly moisture-proof and plied over the outside to prevent abrasion. cheap to manufacture. in the accompanying drawings is illuslt relates to an improvement upon the trated a conductor embodying our improvetype of conductor described in Patent No. \ments, Figure 1 being a side elevation with 666,003, granted to William Le Emmet successive layers of the insulating fabric par- January 15, 1901. In said patent is de tially unwound to show their relative arscribed a form of conductor in which multiran ement. 2 is a cross-secti0n of a ple layers of flexible fabric coated with an incab e embodying our improvements, and Fig. sulating-varnish composed pri'nci ally of lin- 3 is a section of the varnished fabric.

seed-oil were wound over a con uctor, suc- 1 represents the insulated conductor, which cessive layers being coated a number of times may be a single wire or a group of wires. @n 7 5 with the insulating-varnish. Such a form of this are laid a number of windings, as 2 3, of construction, although extremely effective muslin, pa er, or other vegetrdal or organic for insulating purposes, is slow in manufacflexible fa ric, each layer being coated on ture by reason of the time required for the both sides with an insulating-varnish confilms of varnish to dry and harden. ive protaining an excess of an oridizable oil. The mote a much greater expedition n manufaccomposition of this varnish may be varied in ture by preparing the fabric as a preliminary practice; but we find excellent results from stage of the manufacture and carrying the a mixture of about eighty parts of boiled linconductor or cable, after each layer of the seed-oil and twenty of rosin, which may be fabric is applied, through a bath containing thinned for application by a solvent, suchas 8 5 a viscous insulating compound which will efbenzin. The paper may be given more fectively sealthe joints of the winding and than one coat. in practice we find that provide asoft yielding film between the sevtwo coats give superior results. Each layer eral layers,which will permit slipping of one is wound spirally about the-conductor, so as layer uoon another when the conductor or to have the edges abut against one anoth'engo cable is ent, and thereby prevent fracture of thus forming a close s iral. The covered the insulation, enablin it to meet all the reconductor is then led t ough a bath conquirements of practica service without imtaining a compound of rosin, seventy-five per pairing the insulation at some point where a cent, and transil-oil or rectified petroleum, bend is necessarilymade, and thereby impairtwenty-five per cent. The process is reing the insulation of the entire cable. peated for as many layers as deemed neces- We wind as many layers of the coated sary for the voltages the conductor is to fabric upon a core as required for the potenwithstand. Six are shown, by way of exa tial to which the cable is to be subjected, a pie, in the drawing Fig. 2. The rosin comcable havin a dozen layers being capable pound is heated to drive oh moisture and 10c I of withstan ing twentythousand volts and air from the covered conductor and permit upward. In applying the coated fabric to an effective sealin of the joints by the visthe core it is wound in a spiral with buttcous compound. he successive layers are joints, the cable being then passed through a arranged with overlappin joints to more bath of the viscous compound and another eflectively seal the inner ayers against inspiral winding appliedinamanner similar tofiltration of moisture, and the joints are 'ture' of the conductor. joints with the oil "compound, as described in exist would be so long that it would require an extraordinary potential to break it down. The viscous compound is particularly advantageous in permitting a rapid manufac- By' covering the the 'priorp'atent' above referredto, the procv varnishes," orany suitable V whichwill not act'injuriou's' *varnish, maybe employed, the ess'entiaFfeaess' is necessarily much -"slower"'th'an our present process. Thelatte'r; mor'eovenahas he advantageot supplying between the layers a yielding compound which renders the cablemuchntore-flexible and permitting the layers to slide one upon" another when the cablefiis'bent, thereby preventing "cracks in the insulation. Besides," the com ound se ls thejoi'ntsas well as the' spaces'between' the several layers. I

We donot fconzfine' ourselves to the viscous medium describedfias others may 'be'. used "withgreater or "lesser advantage. -Asphalt,1. 've'ry "softjoz'ocerite, a mixture ofro'sin and rosin-oiLrosin andfptroleum-oil, non-drying 'plastic insulation y onthe films of ture bei-ngthe application of a film of plastic.

insulation'to the l joints and between the v layers of a varnished fabric.

What we claim as new, and desire to secure by Letters Patent ofithe- United States, is

1. An insulated electric conductor, covered with a plurality of layers of preliminary varnished and hardened fabric, and a homo-' geneous layer of permanently-viscousinsulating material forming a continuous covering for the layers of fabric.

' 2. An insulated electric conductor, covered with a plurality of layers of flexible fab:

ric preliminarilycoated on both sides with a 'tough,oxidized film of a'vege'table oil, and a layer of permanently-viscous insulatin comfound, forming a continuous covering or the ayers of fabric and applied directly thereto.

An insulated electric conductor, cov- 'eredwith a plurality of layers of fabric, each layer preliminarily coated an both'sides'with "a hard; dry, tough-film of an insulating compoundcontaining oxidized oil in excess and w-oundhelically on the conductor with the edges in contact, successive layers having overlapping joints, and a homogeneous layer of permanently-viscousinsulating material,

forming a continuous covering for the layers of fabric.

' '[In witness whereof we have hereunto set our hands this 7 'd ay of November, 1901.

-WILLIAM L.. R. EMlWET. WALLACE S. CLARK.

' Witnesses I BE JAMIN B. HULL, HELEN ORFORD. 

